Event pipeline benchmark suite

[ti-mo]

We need some benchmarks to establish the event throughput baseline of each component in the pipeline, as well as the pipeline itself.

Important areas to focus on:

• picking binary events from a perf ring buffer and unmarshaling them into AcctEvents
• for each sink provider, turning AcctEvents into the sink's native metric/document type
• given a stream of randomly-generated AcctEvents, how many events can we deliver to certain numbers of registered dummy sinks?

Following this issue, there should be a performance pass to decrease the amount of allocations done in delivering an event.